Effect of Sintering Temperature on Densification, Microstructure, and Corrosion Behavior of Ti6Al4V/20Cu Composites...

Copper alloying of Ti6Al4V via liquid-phase sintering (LPS) is a promising route to enhance densification and mechanical properties for biomedical implants. This study investigates the effect of sintering temperature (900-1100 °C) on the densification, microstructure, and electrochemical behavior of Ti6Al4V-20 wt.% Cu composites. Samples were fabricated via pressureless sintering, maintaining a constant relative green density of 72.7%. The results show that the relative density increased progressively from 78.6% at 900 °C to 98.1% at 1100 °C. Microstructural analysis revealed a transition from fragmented Ti-Cu dendritic structures to refined globular intermetallic, with enhanced copper diffusion into the α-Ti matrix above 1000 °C, accompanied by the formation of TiCu and Ti₂Cu intermetallic phases. Correspondingly, microhardness increased systematically from 313 HV to 473 HV, correlated with reduced porosity and intermetallic reinforcement. Electrochemical tests in Ringer's solution indicated that while higher temperatures improve structural integrity, the distribution of Cu-rich phases significantly influences corrosion kinetics. These findings demonstrate that sintering at 1100 °C optimizes the densification-microstructure relationship, providing a technical basis for the development of high-performance Ti-based composites. Based on previous studies of Ti-Cu systems, these materials may exhibit antibacterial activity, although no biological or antibacterial tests were performed in the present work.